How contagious is swine flu? Less than the novel viruses that have caused big world outbreaks in the past, new research suggests.

If someone in your home has swine flu, your odds of catching it are about one in eight, although children are twice as susceptible as adults, the study found. It is one of the first big scientific attempts to find out how much the illness spreads in homes versus at work or school and who is most at risk.

The study was done by outbreak specialists from Imperial College London and from the U.S. Centers for Disease Control and Prevention. Results are in today’s New England Journal of Medicine.

Swine flu has sickened an estimated one-sixth of Americans since the novel virus was first identified in April. The second wave of cases now seems to have peaked, and health experts do not know whether another surge lies ahead.

Researchers studied infection patterns in 216 people with swine flu from across the U.S. — half of them children — and 600 people living with them.

Respiratory illnesses that researchers assumed were swine flu developed in 78 of the 600 household members, or 13 percent.

However, 10 percent had symptoms more specific to flu.

That’s less than the “spread” rate during earlier flu pandemics in 1957 and 1968, when 14 percent to 20 percent of household members were infected. In an ordinary flu season, the virus spreads to 5 percent to 40 percent of household members, various studies have shown.

Children were twice as susceptible to catching swine flu as adults, and even more so if they were younger than 4, said one of the researchers, Lyn Finelli, surveillance chief for the CDC’s flu division.

Nearly three-fourths of households in the study managed to avoid spreading the illness to any family members.

In homes where the germ was transmitted, researchers found something unexpected: “People at all ages were just as likely to spread the virus,” Finelli said. “That was surprising since we always think of kids as super-spreaders.”

As news of the deadly mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, unfolded last week, Pia Guerra, a 46-year-old Vancouver-based artist, felt helpless. She couldn’t bring herself to go to sleep, so she began to draw.

Police who find suspected drugs during a traffic stop or an arrest usually pause to perform a simple task: They place some of the material in a vial filled with liquid. If the liquid turns a certain color, it’s supposed to confirm the presence of cocaine, heroin or other narcotics.